The Independent's economics editor Sean O'Grady had a very good article on Monday about the benefits of immigration to Britain. The native British population is getting older, he points out, and having fewer children. Where some see the demographic dynamism of immigrants as a threat, O'Grady sees it as an opportunity to revitalize Britain:

To be a productive and prosperous nation we need people, lots of them, and the younger and better skilled the better. Immigrants tend to be young and enterprising. They work harder, often; think of the thousands toiling, yes, often illegally, in sweat shops, cleaning hotels and hospitals, serving behind bars or waiting on tables, driving minicabs at all hours and working in care homes tending to our parents and grandparents. Their children often go into the professions or start their own businesses – like the Kenyan and Ugandan Asians I grew up with in Leicester. . . .

Think of the most vibrant economies in history: America, Argentina and Britain in the 19th-century; western Europe and Japan in the 1960s; China, Brazil, Indonesia and India today; Australia for most of its history. All had rapidly expanding, youthful populations, some of them by attracting immigrants. Contrast them with the sclerotic, ageing economies of today – southern Europe and Japan.

Indeed. Countries become rich and prosperous when they attract people from elsewhere. Many opponents of open borders accuse its advocates of being blind to the cultural arguments, but this is untrue. Consider the American Century, driven (culturally, at least) by the universal appeal of the Hollywood culture. An enormous number of the greatest directors, writers and actors of the Hollywood era were first- or second-generation immigrants, often bringing the techniques and sensibilities of their homelands to the American melting pot.

The Polish-born Roman Polanski (Chinatown), the Greek-born Elia Kazan (On the Waterfront), and the Italian-American Francis Ford Coppola (The Godfather, Apocalypse Now) come to mind – all directors of films speaking to the American experience. Immigrants helped to make American culture what it is. Some will say that Britain is different; that its culture is one of conservatism (in the literal sense) and tradition. Maybe, but British culture has also been influenced by its immigrant groups (and, less happily, by its colonies).

The real problem with immigration, I think, is ghettoization. This is a danger, and one that has already been realized in some parts of the country: certain communities of people being shunted together and creating their own cultural enclaves in urban areas. To an extent this is a natural part of immigration – new arrivals to a country want to be near people they have something in common with – but that isn't the whole story. Successive government housing policies based around Le Corbusier-style council estates have also added to the ghettoization of immigrant groups. Sticking a whole load of people into a housing estate, without property rights over the houses they're in, is bound to generate delinquency and discontent. So too with welfare policies that discourage work and, thus, social mobility. This may explain native resistence to immigration as well – competition for government welfare, a truly fixed pie, is likely to engender resentment and hostility in a way that voluntary exchange never could.

Immigration opponents would do well to recognise the benefits – economic and cultural – of allowing people into Britain. But supporters of open borders should accept that, as things currently stand, there are some downsides. If both could make peace and accept that free movement of people is just as important as the free movement of goods, they could work to dismantle parts of government, the real problem-maker. Then Britain really could be back on the road to greatness.